refactor : simplify codebase and fix critical issues

Backend:
- Add MCP Serializer to centralize entity-to-array conversion (~300 lines deduped)
- Fix race condition in task/ticket number generation (SELECT FOR UPDATE + transaction)
- Add unique constraint on task (project_id, number) with migration
- Fix MIME type validation: use server-detected finfo instead of client-supplied type
- Add allowlist of permitted MIME types for uploads
- Fix TaskDocumentDownloadController: allow ROLE_CLIENT access, add priority:1
- Fix notification sent even when ticket status unchanged
- Remove redundant exception constructors
- Simplify services (BookStackApi double fetch, TokenEncryptor, GiteaApi)
- Consolidate duplicate checks in processors

Frontend:
- Fix useApi isHandlingUnauthorized scope (module-level to prevent double 401 redirect)
- Fix client-tickets toast key copy-paste bug
- Merge duplicated tasks service methods (getByProject + getByProjectArchived)
- Extract shared uploadWithRelation helper in task-documents service
- Extract formatFileSize utility from duplicated component code
- Extract status transition logic into useClientTicketHelpers composable
- Remove dead code (unused router, handleLogout, empty script blocks)
- Merge duplicate watchers and onMounted calls
- Normalize arrow functions to function declarations per convention

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/State/ClientTicketProvider.php

@@ -54,17 +54,27 @@ final readonly class ClientTicketProvider implements ProviderInterface
         // Apply filters from query parameters
         $filters = $context['filters'] ?? [];
         if (isset($filters['project'])) {
-            $projectId = is_numeric($filters['project']) ? (int) $filters['project'] : (int) basename($filters['project']);
-            $qb->andWhere('ct.project = :project')->setParameter('project', $projectId);
+            $qb->andWhere('ct.project = :project')
+                ->setParameter('project', self::extractId($filters['project']))
+            ;
         }
         if (isset($filters['status'])) {
             $qb->andWhere('ct.status = :status')->setParameter('status', $filters['status']);
         }
         if (isset($filters['submittedBy']) && $this->security->isGranted('ROLE_ADMIN')) {
-            $submittedById = is_numeric($filters['submittedBy']) ? (int) $filters['submittedBy'] : (int) basename($filters['submittedBy']);
-            $qb->andWhere('ct.submittedBy = :submittedBy')->setParameter('submittedBy', $submittedById);
+            $qb->andWhere('ct.submittedBy = :submittedBy')
+                ->setParameter('submittedBy', self::extractId($filters['submittedBy']))
+            ;
         }
 
         return $qb->getQuery()->getResult();
     }
+
+    /**
+     * Extract an entity ID from a value that may be a numeric ID or an IRI string.
+     */
+    private static function extractId(string $value): int
+    {
+        return is_numeric($value) ? (int) $value : (int) basename($value);
+    }
 }